1. Technical Field
The present disclosure generally relates to a magnetic device, and more particularly to a magnetic element such as a magnetic tunnel junction (MTJ) element.
2. Related Art
Nonvolatile memory devices which use a resistance material to store a data state include a phase change random access memory (PRAM), a resistive RAM (RRAM), a magnetic RAM (MRAM), and the like. A dynamic RAM (DRAM) or flash memory device stores data using electrical charges, whereas a nonvolatile memory device having a resistance material stores data using the variable states of the resistance material, for instance, using a phase change of a phase change material such as a chalcogenide alloy (in the case of a PRAM), a resistance change of a variable resistance material (in the case of an RRAM), or a resistance change of a magnetic tunnel junction (MTJ) depending on a magnetization state of a ferromagnetic material (in the case of an MRAM).
An MTJ element typically has a pinned layer formed of a ferromagnetic material and a free layer formed of a ferromagnetic material, which are separated from each other by an insulating layer that is used as a tunnel barrier. At an edge of the ferromagnetic material, a stray field may be generated. This stray field may lower the magnetic resistance or increase the coercive force of the free layer, and exert an influence on the switching characteristic to form asymmetric switching. Accordingly, there is a need for a structure that can reduce or remove the stray field that is generated in the ferromagnetic material of the MTJ element.